1. Field of the Invention
The present invention generally relates to a manual control part of an endoscope, more particularly to a manual control part of an endoscope with a grip which can be easily held by an operator in one hand.
2. Description of Related Art
A manual control part of an endoscope for medical use comprises a grip held by an operator in one hand, and a control part with a knob for curving control and air and water supply buttons. Grips with various shapes have been suggested to be easily held.
Japanese Utility Model Application Laid-Open No. 57-109804 discloses a grip in which the middle part between both sides is thinner than at least one of the sides. It exemplifies a grip whose transverse section is a trapezoid in which one side the fingers of the operator touch is thick and the thickness is gradually reduced toward the other side the palm of the operator touches. Moreover, it also exemplifies a grip in which the middle part and the side the palm touches are of the same thickness and thinner than the side the fingers touch.
In above-mentioned Japanese Utility Model Application Laid-Open No. 57-109804, however, it is difficult for the operator to contact the fingers and the palm with the surface of the grip since the transverse section of the grip is substantially quadrilateral, and thus the grip cannot be securely held.
In addition, the side the fingers touch is thicker than the other parts, and thus the palm may lose contact with the grip. Therefore, a satisfactory grip cannot be guaranteed.
The present invention has been developed in view of the above-described circumstances, and has as its object the provision of a manual control part of the endoscope with a grip that can be firmly held.
In order to achieve the above-described object, the present invention is directed to a manual control part of an endoscope with a grip held by an operator in one hand, wherein: a transverse section of the grip is formed in such a manner that first and second arches are connected with one another, the first and second arches having centers inside the grip and radii of curvature different from one another, the first arch touching pads of fingers of the hand, the second arch touching a palm of the hand; the radius of curvature of the first arch is larger than the radius of curvature of the second arch; and a part of the grip formed by the first arch is thinner than a part of the grip formed by the second arch.
According to the invention, since the transverse section of the grip is formed in such a manner that the two arches with centers inside the grip and with the different radii of curvature are connected with each other, the fingers and the palm can be firmly contacted with the surface of the grip. Moreover, the radius of curvature of one arch the finger pads of the hand touch is larger than that of the other arch the palm of the hand touches, and the part of the grip formed by the arch the finger pads touch is thinner than the part formed by the arch the palm touches. Thus, when the finger pads are firmly contacted with the arch at the one side, the palm can be naturally contacted firmly with the arch at the other side. Therefore, the grip of the present invention can be securely held by the operator.
Preferably, a circle including the arch the palm touches is inside a circle including the arch the finger pads touch. Thus, the section area of the grip is small and the manual control part can be small.
Preferably, a step is formed at a boundary between the two arches as a stopper for fingertips. Thus, the grip can be more easily held.